Fix parseStream bug

Hopding · Jul 6, 2018 · c3925c9 · c3925c9
1 parent 75f1417
commit c3925c9
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Showing 2 changed files with 43 additions and 14 deletions.
diff --git a/src/core/pdf-parser/parseStream.ts b/src/core/pdf-parser/parseStream.ts
@@ -1,6 +1,12 @@
 import { PDFDictionary, PDFName, PDFRawStream } from 'core/pdf-objects';
 import { PDFObjectStream } from 'core/pdf-structures';
-import { arrayIndexOf, arrayToString, error, trimArray } from 'utils';
+import {
+  arrayIndexOf,
+  arrayIndexOneOf,
+  arrayToString,
+  error,
+  trimArray,
+} from 'utils';
 
 import PDFObjectIndex from 'core/pdf-document/PDFObjectIndex';
 
@@ -37,11 +43,13 @@ const parseStream = (
   dictionary to jump to the end of the stream, instead of traversing each byte.
   */
   // Locate the end of the stream
-  const endstreamIdx =
-    arrayIndexOf(trimmed, '\nendstream') ||
-    arrayIndexOf(trimmed, '\rendstream') ||
-    arrayIndexOf(trimmed, 'endstream');
-  if (!endstreamIdx && endstreamIdx !== 0) error('Invalid Stream!');
+  const endstreamMatchTuple = arrayIndexOneOf(trimmed, [
+    '\nendstream',
+    '\rendstream',
+    'endstream',
+  ]);
+  if (!endstreamMatchTuple) error('Invalid Stream!');
+  const [endstreamIdx, endstreamMatch] = endstreamMatchTuple!;
 
   /*
   TODO: See if it makes sense to .slice() the stream contents, even though this
@@ -56,7 +64,7 @@ const parseStream = (
     error('Invalid Stream!');
   }
 
-  return [contents, trimmed.subarray(endstreamIdx + 10)];
+  return [contents, trimmed.subarray(endstreamIdx + endstreamMatch.length)];
 };
 
 /**

diff --git a/src/utils/index.ts b/src/utils/index.ts
@@ -69,7 +69,7 @@ export const charCodes = (str: string) =>
 export const typedArrayFor = (str: string) => new Uint8Array(charCodes(str));
 
 export const arrayToString = (
-  arr: Uint8Array,
+  arr: Uint8Array | number[],
   startAt = 0,
   stopAt?: number,
 ) => {
@@ -112,12 +112,6 @@ export const arrayIndexOf = (
   targetStr: string,
   startFrom = 0,
 ) => {
-  // validate(
-  //   startFrom,
-  //   and(_.isNumber, not(_.isNaN)),
-  //   `startFrom must be a number, found: "${startFrom}"`,
-  // );
-
   const targetArr = targetStr.split('').map((c) => c.charCodeAt(0));
   let currIdx = startFrom;
 
@@ -138,6 +132,33 @@ export const arrayIndexOf = (
   return currIdx;
 };
 
+export const arrayIndexOneOf = (
+  arr: any[] | Uint8Array,
+  targetStrings: string[],
+  startFrom = 0,
+): [number, string] | void => {
+  const targetArrs = targetStrings.map((str) => str.split('').map(charCode));
+  let currIdx = startFrom;
+  let match = null;
+
+  while (!match) {
+    currIdx += 1;
+    if (currIdx >= arr.length) return undefined;
+    match = targetArrs.find((target) =>
+      arraysAreEqual(
+        arr,
+        currIdx,
+        currIdx + target.length,
+        target,
+        0,
+        target.length,
+      ),
+    );
+  }
+
+  return [currIdx, arrayToString(match)];
+};
+
 export const arrayIndexOfReverse = (
   arr: any[],
   targetStr: string,